Electronic apparatus having flexible display device

ABSTRACT

A disclosed electronic device includes a housing having an opening, a roll mounted in the housing, a flexible display wound on the roll and being extendable and retractable through the opening based on a rotation direction of the roll, and a roll guide configured to guide the roll to move in a direction capable of constantly maintaining a proceeding direction of the flexible display toward the opening in the housing, based on a variation in a wound length of the flexible display on the roll.

TECHNICAL FIELD

The present disclosure relates to electronic devices, and moreparticularly, to structures in which flexible displays are extendableout of or retractable into electronic devices.

BACKGROUND ART

Currently, display devices are regarded as essential electronicproducts. Electronic devices are required to be of compact size but manycustomers also desire large screens. Therefore, research and developmentare being actively conducted on flexible displays which are foldable orrollable into electronic devices.

DETAILED DESCRIPTION OF THE INVENTION Technical Problem

Provided are electronic devices capable of minimizing damage to flexibledisplays when the flexible displays extend out of or retract into theelectronic devices.

Technical Solution

According to an aspect of an embodiment, an electronic device includes ahousing having an opening, a roll mounted in the housing, a flexibledisplay wound on the roll and being extendable and retractable throughthe opening based on a rotation direction of the roll, and a roll guideconfigured to guide the roll to move in a direction capable ofmaintaining a proceeding direction of the flexible display toward theopening in the housing, based on a variation in a wound length of theflexible display on the roll.

The electronic device may further include a central shaft serving as anaxis of rotation of the roll, and the roll guide may guide the centralshaft.

The electronic device may further include a winding member configured toprovide elastic force in a direction capable of winding the flexibledisplay on the roll.

The electronic device may further include a locking unit configured tolock the roll so as not to rotate in a direction of the elastic force ofthe winding member.

The locking unit may include a stopper projection provided on the roll,and a stopper lever having a release location where interference withthe stopper projection is released, and a contact location where thestopper lever is obstructed by the stopper projection to stop rotationof the roll.

The roll guide may guide the roll to move in a direction perpendicularto the proceeding direction of the flexible display toward the openingin the housing.

The roll guide may guide the roll to move diagonally to a directionperpendicular to the proceeding direction of the flexible display towardthe opening.

The electronic device may further include a display guide having asupporting surface configured to support the flexible display and guidethe flexible display unwound from the roll, toward the opening.

The electronic device may further include a guide member configured toguide the flexible display at a side opposite to the display guide withrespect to the flexible display interposed between the guide member andthe display guide.

The guide member may guide the flexible display to proceed in ahorizontal direction after passing through the opening.

The electronic device may further include a push member configured topush the roll toward the display guide in such a manner that theflexible display wound on the roll contacts the supporting surface.

The electronic device may further include an elastic member configuredto provide elastic force to push the push member toward the displayguide.

The push member may include a roller rotating in contact with theflexible display.

The push member may include a roll spring supported by the roll guideand pushing the roll toward the display guide.

The electronic device may further include a pinion gear rotatingtogether with the roll, and a rack gear connected to the pinion gear andextending in an extension direction of the roll guide.

The electronic device may further include one or more reduction gearsinterposed between the pinion gear and the rack gear.

According to another aspect of an embodiment, an electronic deviceincludes a housing having an opening, a roll mounted in the housing, anda flexible display having an end connected to the roll, wound on theroll, and being extendable and retractable through the opening based ona rotation direction of the roll, wherein the roll moves to constantlymaintain a proceeding angle of the flexible display toward the openingin the housing.

The electronic device may further include a central shaft serving as anaxis of rotation of the roll, and a roll guide configured to guide thecentral shaft in a direction capable of constantly maintaining theproceeding angle.

The roll guide may guide the roll to move in a direction perpendicularto a proceeding direction of the flexible display toward the opening inthe housing.

The roll guide may guide the roll to move diagonally to a directionperpendicular to a proceeding direction of the flexible display towardthe opening.

According to another aspect of an embodiment, an electronic deviceincludes a housing having an opening, a roll mounted in the housing, aflexible display wound on the roll and being extendable and retractablethrough the opening based on a rotation direction of the roll, asupporting surface configured to support the flexible display wound onthe roll, and a roll guide configured to guide the roll to move towardthe supporting surface as the flexible display is unwound from the roll.

The supporting surface may extend toward the opening to guide theflexible display unwound from the roll, toward the opening.

The electronic device may further include a push member configured topush the roll toward the supporting surface.

The electronic device may further include an elastic member configuredto provide elastic force to push the push member toward the supportingsurface.

The push member may include a roller rotating in contact with theflexible display wound on the roll.

The electronic device may further include a guide member configured toguide the flexible display toward the opening at a side opposite to thesupporting surface.

The electronic device may further include a pinion gear rotatingtogether with the roll, and a rack gear connected to the pinion gear andextending in an extension direction of the roll guide.

The electronic device may further include one or more reduction gearsinterposed between the pinion gear and the rack gear.

Advantageous Effects of the Invention

According to an embodiment, when a flexible display extends out of anelectronic device, a roll having the flexible display wound thereon maymove to reduce a load applied to the flexible display.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a network environment including anelectronic device according to an embodiment.

FIG. 2 is a perspective view of an electronic device according to anembodiment.

FIG. 3 is a perspective view of a roll included in an electronic device,and a flexible display wound on the roll, according to an embodiment.

FIG. 4 is a side cross-sectional view showing that a flexible display iswound or unwound when a roll rotates at a fixed location.

FIGS. 5 and 6 are side cross-sectional views of an electronic deviceaccording to an embodiment.

FIG. 7 is a side cross-sectional view showing that a roll of anelectronic device moves toward an opening, according to an embodiment.

FIG. 8 is a side cross-sectional view of an electronic device includinga display guide, according to embodiment.

FIG. 9 is a side cross-sectional view of an electronic device includinga push member, according to embodiment.

FIGS. 10 and 11 are side cross-sectional views of an electronic deviceincluding a winding member, according to embodiment.

FIG. 12 is a structural view of a locking unit according to anembodiment.

FIGS. 13 and 14 are side cross-sectional views of an electronic deviceincluding a roll spring, according to an embodiment.

FIGS. 15 and 16 are side cross-sectional views of an electronic deviceincluding a pinion gear and a rack gear, according to an embodiment.

FIGS. 17 and 18 are structural views of a reduction gear(s) of anelectronic device, according to embodiments.

FIGS. 19 and 20 are perspective views showing that a flexible displayextends out of an electronic device, according to embodiments.

MODE OF THE INVENTION

Hereinafter, various embodiments of the present disclosure are describedin detail with reference to the accompanying drawings. However, thisdescription is not intended to limit the present disclosure to thedescribed embodiments and it should be understood that the presentdisclosure covers all modifications, equivalents, and/or alternativesthereof. In the drawings, like reference numerals denotes like elements.

As used herein, terms such as “have”, “may have”, “include”, “mayinclude”, “comprise”, and “may comprise” specify the presence of statedfeatures (e.g., values, functions, operations, or elements), but do notpreclude the presence or addition of one or more other features.

The expressions “A or B”, “at least one of A or/and B”, or “one or moreof A or/and B” used herein include any and all combinations of one ormore of the listed items. For example, “A or B”, “at least one of A andB”, or “at least one of A or B” means (1) including at least one A, (2)including at least one B, or (3) including both at least one A and atleast one B.

Terms such as “1st”, “2nd”, “first”, and “second” may be used herein todescribe various elements regardless of order and/or priority thereof,but these elements should not be limited by these terms. These terms areonly used to distinguish one element from another. For example, “a firstuser device” and “a second user device” may indicate different userdevices regardless of order and/or priority thereof. For example, afirst element could be termed a second element and, similarly, a secondelement could be termed a first element without departing from the scopeof the present disclosure.

It will be understood that when an element (e.g., first element) isreferred to as being “(operatively or communicatively) coupled with/to”or “connected to” another element (e.g., second element), the elementcan be directly coupled or connected to the other element or anintervening element (e.g., third element) may be present. Conversely,when an element (e.g., first element) is referred to as being “directlycoupled” or “directly connected” to another element (e.g., secondelement), there is no intervening element (e.g., third element) present.

The expression “configured to” may be interchangeably used with“suitable for”, “having the capacity to”, “designed to”, “adapted to”,“made to”, or “capable of” according to the context. The expression“configured to” does not necessarily mean “specifically designed to” interms of hardware. Instead, the expression “a device configured to . . .” may mean that the device is “capable of . . . ” along with otherdevices or parts in a certain situation. For example, “a processorconfigured to perform A, B, and C” may mean a dedicated processor (e.g.,an embedded processor) for performing the operations or ageneric-purpose processor (e.g., a central processing unit (CPU) orapplication processor) for performing the operations by executing atleast one software program stored in a memory device.

Terms used herein are used merely to describe certain embodiments and donot limit the scope of the present disclosure. Singular forms mayinclude plural forms as well unless the context explicitly indicatesotherwise. Unless defined differently, all terms used in the descriptionincluding technical and scientific terms have the same meaning asgenerally understood by one of ordinary skill in the art. Terms asdefined in a commonly used dictionary should be construed as having thesame meaning as in an associated technical context, and unless definedin the description, the terms are not ideally or excessively construedas having formal meaning. In any case, even the terms defined in thisspecification cannot be interpreted as excluding embodiments of thepresent disclosure.

Electronic devices described herein according to various embodiments mayinclude at least one of, for example, smartphones, tablet personalcomputers (PCs), mobile phones, video phones, electronic book (e-book)readers, desktop PCs, laptop PCs, netbook computers, workstations,servers, personal digital assistants (PDAs), portable multimedia player(PMI's), MP3 players, mobile medical devices, cameras, and wearabledevices. According to various embodiments, the wearable devices mayinclude at least one of accessory type wearable devices (e.g., watches,rings, bracelets, ankle bracelets, necklaces, glasses, andhead-mounted-devices (HMDs)), textile/clothing type wearable devices(e.g., electronic apparel), body-attached wearable devices (e.g., skinpads and tattoos), and body-implantable wearable devices (e.g.,implantable circuits).

In some embodiments, the electronic devices may be home appliances. Thehome appliances may include at least one of, for example, televisions(TVs), digital versatile disc (DVD) players, audio players,refrigerators, air conditioners, cleaners, washing machines, aircleaners, set-top boxes, home automation control panels, securitycontrol panels, TV boxes (e.g., Samsung HomeSync™, Apple TV™, and GoogleTV™), game consoles (e.g., Xbox™ and PlayStation™), electronicdictionaries, electronic keys, camcorders, and electronic pictureframes.

In other embodiments, the electronic devices may include at least one ofvarious medical devices (e.g., various portable medical measurementdevices such as blood glucose meters, heart rate meters, blood pressuremeters, and thermometers, magnetic resonance angiography (MRA) devices,magnetic resonance imaging (MRI) devices, computed tomography (CT)devices, scanners, and ultrasonic devices), navigation devices, globalnavigation satellite systems (GNSSs), event data recorders (EDRs),flight data recorders (FDRs), vehicle infotainment devices, electronicequipment for vessels (e.g., vessel navigation systems andgyrocompasses), avionics, security devices, vehicle head units,industrial or home robots, automatic teller machines (ATMs), point ofsales (POS) devices, and Internet of Things (IoT) devices (e.g., lamps,various sensors, electricity or gas meters, sprinklers, fire alarms,thermostats, streetlamps, toasters, exercise equipment, hot water tanks,heaters, and boilers).

According to an embodiment, the electronic devices may include at leastone of parts of furniture or buildings/structures, electronic boards,electronic signature receiving devices, projectors, or various measuringinstruments (e.g., water meters, electricity meters, gas meters, andradio wave meters). In various embodiments, the electronic device may beone or a combination of two or more of the above-mentioned devices. Theelectronic device according to an embodiment may be a flexibleelectronic device. However, the electronic devices according toembodiments are not limited to the above-mentioned devices, but mayinclude new electronic devices to be developed.

FIG. 1 is a block diagram of a network environment 100 including anelectronic device 101 according to various embodiments.

Referring to FIG. 1, the electronic device 101 may include a bus 110, aprocessor 120, a memory 130, an input/output interface 140, and adisplay 150.

The bus 110 may be a circuit for interconnecting the above-mentionedelements and transmitting communication data (e.g., control messages)between the above-mentioned elements.

The processor 120 may, e.g., receive instructions from theabove-mentioned other elements (e.g., the memory 130, the input/outputinterface 140, the display 150, and a communication interface 160)through the bus 110, interpret the received instructions, and performcalculation or data processing based on the interpreted instructions.

The memory 130 may store instructions or data received from theprocessor 120 or the other elements (e.g., the input/output interface140, the display 150, and the communication interface 160) or generatedby the processor 120 or the other elements. The memory 130 may includeprogramming modules, e.g., a kernel 131, middleware 132, an applicationprogramming interface (API) 133, and applications 134. Each of theabove-mentioned programming modules may be configured as software,firmware, hardware, or a combination of two or more thereof.

The kernel 131 may control or manage system resources (e.g., the bus110, the processor 120, or the memory 130) which are used to performoperations or functions implemented in the other programming modules,e.g., the middleware 132, the API 133, or the applications 134. Inaddition, the kernel 131 may provide an interface for allowing themiddleware 132, the API 133, or the applications 134 to access andcontrol or manage each element of the electronic device 101.

The middleware 132 may serve as a relay for allowing the API 133 or theapplications 134 to communicate and exchange data with the kernel 131.In addition, the middleware 132 may control (e.g., schedule orload-balance) operation requests received from the applications 134 by,for example, giving a priority of using the system resources (e.g., thebus 110, the processor 120, or the memory 130) of the electronic device101 to at least one of the applications 134.

The API 133 may be an interface for allowing the applications 134 tocontrol a function provided by the kernel 131 or the middleware 132, andmay include at least one interface or function (e.g., an instruction)for, for example, file control, window control, image processing, ortext control.

According to various embodiments, the applications 134 may include ashort message service (SMS)/multimedia message service (MMS)application, an e-mail application, a calendar application, an alarmapplication, a healthcare application (e.g., an application formeasuring a workrate or a blood glucose level), and an environmentalinformation application (e.g., an application for providing informationabout atmospheric pressure, humidity, or temperature). Additionally oralternatively, the applications 134 may be applications related toinformation exchange between the electronic device 101 and an externalelectronic device (e.g., an electronic device 104).

The application related to information exchange may include, forexample, a notification relay application for transmitting certaininformation to the external electronic device or a device managementapplication for managing the external electronic device.

For example, the notification relay application may include a functionfor transmitting notification information generated from the otherapplication of the electronic device 101 (e.g., the SMS/MMS application,the e-mail application, the health management application, or theenvironmental information application), to the external electronicdevice (e.g., the electronic device 104). Additionally or alternatively,the notification relay application may receive notification informationfrom, for example, the external electronic device (e.g., the electronicdevice 104) and provide the received notification information to a user.The device management application may manage (e.g., install, delete, orupdate), for example, functions related to at least a part of theexternal electronic device (e.g., the electronic device 104)communicating with the electronic device 101 (e.g., functions forturning on/off the external electronic device (or some parts thereof) oradjusting brightness (or resolution) of a display), and applicationsoperating in the external electronic device or services provided by theexternal electronic device (e.g., a call service or a message service).

According to various embodiments, the applications 134 may include anapplication that is designated based on properties (e.g., the type) ofthe external electronic device (e.g., the electronic device 104). Forexample, when the external electronic device is an MP3 player, theapplications 134 may include an application related to reproduction ofmusic. Similarly, when the external electronic device is a mobilemedical device, the applications 134 may include an application relatedto healthcare. According to an embodiment, the applications 134 mayinclude at least one of an application designated for the electronicdevice 101 and an application received from an external electronicdevice (e.g., a server 106 or the electronic device 104).

The input/output interface 140 may transmit an instruction or data inputfrom the user through an input/output device (e.g., a sensor, akeyboard, or a touchscreen) to the processor 120, the memory 130, or thecommunication interface 160 through, for example, the bus 110. Forexample, the input/output interface 140 may provide, to the processor120, data about the user's touch input through the touchscreen. Inaddition, the input/output interface 140 may output, through aninput/output device (e.g., a speaker or a display), an instruction ordata received from the processor 120, the memory 130, or thecommunication interface 160 through, for example, the bus 110. Forexample, the input/output interface 140 may output voice data processedby the processor 120, to the user through the speaker.

The display 150 may display various types of information (e.g.,multimedia data and text data) to the user. The display 150 may include,for example, a liquid crystal display (LCD), a light-emitting diode(LED) display, an organic light-emitting diode (OLED) display, amicroelectromechanical system (MEMS) display, an electronic paperdisplay, or a flexible display. The display 150 may, for example,display various contents (e.g., text, images, videos, icons, andsymbols) to the user. The display 150 may include a touchscreen and mayreceive, for example, touches, gestures, proximity touches, or hoveringinputs using an electronic pen or a body part of the user.

The electronic device 101 may further include the communicationinterface 160. The communication interface 160 may establish acommunication connection between the electronic device 101 and theexternal device (e.g., the electronic device 104 or the server 106). Forexample, the communication interface 160 may be connected to a network162 through wireless or wired communication to communicate with theexternal device. The wireless communication technology may include atleast one of, for example, wireless fidelity (Wi-Fi), Bluetooth (BT),near field communication (NFC), global positioning system (GPS), andcellular communication (e.g., long term evolution (LTE), LTE-advanced(LTE-A), code division multiple access (CDMA), wideband CDMA (WCDMA),universal mobile telecommunication system (UMTS), wireless-broadband(WiBro), and global system for mobile communications (GSM)). The wiredcommunication technology may include at least one of, for example,universal serial bus (USB), high definition multimedia interface (HDMI),recommended standard 232 (RS-232), and plain old telephone service(POTS).

According to an embodiment, the network 162 may be a telecommunicationsnetwork. The telecommunications network may include at least one of acomputer network, the Internet, the Internet of things, or a telephonenetwork. According to an embodiment, a protocol (e.g., a transport layerprotocol, a data link layer protocol, or a physical layer protocol) forcommunication between the electronic device 101 and the external devicemay be supported by at least one of the applications 134, the API 133,the middleware 132, the kernel 131, and the communication interface 160.

FIG. 2 is a perspective view of the electronic device 101 according toan embodiment. FIG. 3 is a perspective view of a roll 300 included inthe electronic device 101, and a flexible display 310 wound on the roll300.

Referring to FIGS. 2 and 3, the electronic device 101 may include ahousing 200, the roll 300 on which the flexible display 310 is wound,and the flexible display 310 wound on the roll 300 to retract into thehousing 200 or unwound from the roll 300 to extend out of the housing200.

The electronic device 101 has a structure capable of accommodating theflexible display 310 in the housing 200 in a wound state, and ofextending and spreading the display 310 out of the housing 200 asnecessary to provide information to a user.

To this end, an opening 400 is provided in a surface or at a side of thehousing 200. The flexible display 310 may be unwound from the roll 300and may extend out of the electronic device 101 through the opening 400of the housing 200. When wound on the roll 300, the flexible display 310may retract into the housing 200 through the opening 400.

An end of the flexible display 310 is connected to the roll 300. Theflexible display 310 may be connected to the roll 300 directly orthrough a medium for transmitting signals between the flexible display310 and the electronic device 101.

The roll 300 may rotate in the housing 200 to wind the flexible display310 on a body of the roll 300. A handle 210 holdable by the user toextend the flexible display 310 out of the housing 200 may be providedat the other end of the flexible display 310.

A side protector 320 is provided at a width-direction side and the otherwidth-direction side of the flexible display 310. The side protector 320may protect the flexible display 310 from external impact. The sideprotector 320 may be thicker than the flexible display 310.

Referring to FIG. 3, when the flexible display 310 is wound on the roll300 in a multilayer structure, a distance between an inner layer 311 andan outer layer 312 may be constantly maintained such that an outersurface of the inner layer 311 may not contact an inner surface of theouter layer 312. As such, wear and damage of the surface of the flexibledisplay 310, i.e., a display surface on which an image is displayed, maybe reduced.

A central shaft 330 of the roll 300 is rotatably supported in thehousing 200. The roll 300 rotates with respect to the central shaft 330of the roll 300 in the housing 200. The electronic device 101 mayfurther include a winder 220 for rotating the roll 300. The winder 220may be connected from outside the housing 200 to the central shaft 330directly or through a motive power transmission device such as a gear,but is not limited thereto. The flexible display 310 may be wound on theroll 300 by rotating the roll 300 by using the winder 220.

When the roll 300 rotates, the flexible display 310 connected to theroll 300 is wound on or unwound from the roll 300. For example, when theuser pulls the handle 210, the roll 300 rotates in a counterclockwisedirection and the flexible display 310 is unwound from the roll 300 andextends out of the housing 200. When the user rotates the winder 220connected to the central shaft 330 of the roll 300, the roll 300 rotatesin a clockwise direction. Then, the flexible display 310 is wound on theroll 300 and retracts into the housing 200.

A stopper 350 may be mounted on a region of the flexible display 310 oron a region of the side protector 320. An area of the flexible display310 extending out of the housing 200 may be determined based on alocation of the stopper 350. For example, referring to FIG. 3, thestopper 350 may be mounted adjacent to the end of the flexible display310 connected to the roll 300. As such, the flexible display 310 mayextend outside only to where the stopper 350 is mounted.

In the electronic device 101 according to an embodiment, a part fromwhere the stopper 350 is mounted to where the handle 210 is provided maybe configured as the flexible display 310 and a part from where theflexible display 310 is connected to the roll 300 to where the stopper350 is mounted may be configured as a component for transmittingelectronic signals between the processor 120 and the flexible display310 of the electronic device 101. In other words, in the flexibledisplay 310, a region from where the stopper 350 is mounted to the otherend where the handle 210 is provided may be an image display area fordisplaying an image, and a region from the end connected to the roll 300to where the stopper 350 is mounted may be a signal transmission area onwhich a flexible printed circuit board (FPCB) or the like is provided totransmit/receive signals to/from the processor 120.

When the flexible display 310 is wound on or unwound from the roll 300,a distance from a center of the roll 300 to the flexible display 310wound on the roll 300, i.e., an outer diameter of the roll 300, isincreased or reduced. As such, although not shown in FIGS. 2 and 3, theflexible display 310 moves in a direction almost perpendicular to adirection in which the flexible display 310 is unwound from or wound onthe roll 300, i.e., a radius direction of the roll 300. The movement ofthe flexible display 310 in the radius direction may cause shaking of ascreen.

FIG. 4 is a side cross-sectional view showing that the flexible display310 is wound or unwound when the roll 300 rotates at a fixed location.As illustrated in FIG. 4, when the opening 400 of the housing 200 doesnot have a sufficient height, a proceeding direction of the flexibledisplay 310 with respect to the opening 400 in the housing 200 may becontinuously changed and thus the opening 400 may be damaged.

In a first state in which the flexible display 310 is completely woundon the roll 300 as indicated by a solid line in FIG. 4, the flexibledisplay 310 passes through the opening 400 in an almost horizontaldirection. However, in a second state in which the flexible display 310is completely unwound from the roll 300 as indicated by a two-dot chainline in FIG. 4, the flexible display 310 passes through the opening 400in a direction inclined with respect to the direction of the first stateby an angle α. Since the flexible display 310 is repeatedly bent whileextending/retracting, fatigue may be accumulated and thus the flexibledisplay 310 may be damaged.

A method capable of reducing repeated bending of the flexible display310 in a direction perpendicular to a direction of the flexible display310 that enters and exits the housing 200 through the opening 400, andof constantly maintaining a proceeding direction of the flexible display310 with respect to the opening 400 in the housing 200 may beconsidered.

As an example of the method, the roll 300 may be supported in thehousing 200 to move in a direction capable of compensating for avariation in the outer diameter thereof. For example, the roll 300 maybe guided by a roll guide 340 provided in the housing 200. The rollguide 340 may have, for example, a slot shape, and two ends of thecentral shaft 330 of the roll 300 are inserted into a pair of rollguides 340. Due to the above-described configuration, the roll 300 maymove along the roll guide 340 in accordance with the variation in theouter diameter thereof. The movement of the roll 300 may occursimultaneously with rotation of the roll 300.

Embodiments of a structure in which the roll 300 moves in accordancewith a variation in a wound length of the flexible display 310 on theroll 300 will now be described.

FIGS. 5 and 6 are side cross-sectional views of the electronic device101 according to an embodiment. FIG. 5 shows a state in which theflexible display 310 is completely wound on the roll 300, and FIG. 6shows a state in which the flexible display 310 is completely unwoundfrom the roll 300.

Referring to FIG. 5, an end of the flexible display 310 is connected tothe roll 300 and the other end thereof is connected to the handle 210.The flexible display 310 is wound on the roll 300 and is positioned inthe housing 200. When the flexible display 310 extends out of thehousing 200, the roll 300 and the central shaft 330 rotate together. Inthis case, the roll 300 may rotate with respect to the central shaft330, and the central shaft 330 may be supported by the housing 200 tomove along the roll guide 340. Referring to FIG. 6, the flexible display310 is unwound from the roll 300 and extends out of the housing 200.

When the flexible display 310 extends out of the housing 200, an outerdiameter of the roll 300 varies. When the outer diameter of the roll 300in FIG. 5 is D1, the outer diameter of the roll 300 in FIG. 6 is D2 lessthan D1. The roll guide 340 guides the roll 300 in such a manner thatthe roll 300 moves to compensate for a variation (D1-D2) in the outerdiameter of the roll 300. Herein, each of the outer diameters D1 and D2refers to a total outer diameter including the flexible display 310wound on the roll 300.

In FIGS. 5 and 6, the roll guide 340 guides the central shaft 330 insuch a manner that the roll 300 moves downward as the flexible display310 extends from the housing 200. In the current embodiment, a displayguide 920 is positioned under the roll 300 in the direction of gravity,and supports the flexible display 310 wound on the roll 300. The displayguide 920 extends toward the opening 400 in a direction equal to adirection in which the flexible display 310 extends out of the housing200. The display guide 920 is provided adjacent to the opening 400.

Although the display guide 920 is positioned at a lower side in thedirection of gravity in the following description for convenience ofexplanation, the electronic device 101 may be used in a state in whichthe central shaft 330 of FIGS. 5 and 6 stands upright in the directionof gravity. In this case, the location of the display guide 920 is notunder the roll 300 in the direction of gravity, and the display guide920 may extend toward the opening 400 in a direction equal to adirection in which the flexible display 310 extends out of the housing200.

When the flexible display 310 extends or retracts, the display guide 920may contact the surface of the flexible display 310 or the sideprotector 320 of the flexible display 310 to reduce shaking of theflexible display 310. Therefore, as the flexible display 310 is unwoundfrom the roll 300, the roll 300 is guided by the roll guide 340 to movedownward and a movement distance thereof is limited by the display guide920.

The display guide 920 guides the flexible display 310 toward the opening400. The display guide 920 of the current embodiment guides the flexibledisplay 310 to pass through the opening 400 in a horizontal direction.To this end, a supporting surface 921 of the display guide 920, whichsupports the flexible display 310, extends toward the opening 400.

As such, a proceeding direction of a part of the flexible display 310positioned in the housing 200, i.e., a part of the flexible display 310between the roll 300 and the opening 400, may be constantly maintainedas a certain direction, e.g., a horizontal direction. Although not shownin FIGS. 5 and 6, when the electronic device 101 is used in a state inwhich the central shaft 330 stands upright in the direction of gravity,the proceeding direction of the flexible display 310 may be constantlymaintained as a vertical direction.

The roll guide 340 extends in the direction of gravity, i.e., adirection almost perpendicular to a proceeding direction of the flexibledisplay 320 unwound from the roll 300 and proceeding toward the opening400 in the housing 200, in FIGS. 5 and 6, but is not limited thereto.The roll guide 340 may have various shapes capable of compensating forthe variation (D1-D2) in the outer diameter of the roll 300.

FIG. 7 is a side cross-sectional view of the electronic device 101according to an embodiment.

Referring to FIG. 7, the roll guide 340 is inclined downward withrespect to the direction of gravity. In other words, the roll guide 340is inclined with respect to a proceeding direction of the flexibledisplay 320 unwound from the roll 300 and proceeding toward the opening400 in the housing 200. In this case, the inclined direction of the rollguide 340 may be a direction toward the opening 400. As such, a distancebetween the roll 300 and the opening 400 may be reduced and thus alength of an effective image display area of the flexible display 310may be increased.

Since the roll 300 rotates and moves as described above, the flexibledisplay 310 unwound from the roll 300 may always proceed toward theopening 400 in the same direction. That is, a part of the flexibledisplay 310 between the roll 300 and the opening 400 may constantlymaintain the same proceeding direction toward the opening 400 in a statein which the flexible display 310 is positioned in the housing 200, astate in which a part of the flexible display 310 extends out of thehousing 200, and a state in which an extendable area of the flexibledisplay 310 completely extends out of the housing 200.

The proceeding direction of the flexible display 310 for interconnectingthe roll 300 and the opening 400 may not be a horizontal direction. FIG.8 is a side cross-sectional view of the electronic device 101 accordingto embodiment.

Referring to FIG. 8, the display guide 920 includes a supporting surface922 inclined with respect to a horizontal direction. For example, in thecurrent embodiment, the supporting surface 922 is inclined downwardtoward the opening 400. Due to the above-described configuration, as theflexible display 310 is unwound from the roll 300, the roll 300 may benaturally guided by the roll guide 340 to move downward, and theflexible display 310 unwound from the roll 300 may be guided along thesupporting surface 922 to extend out of the housing 200 through theopening 400.

Therefore, a proceeding direction of a part of the flexible display 310between the roll 300 and the opening 400 may be constantly maintained. Aguide member 800 for guiding the proceeding direction of the flexibledisplay 310 passing through the opening 400 may be provided at an upperside of the opening 400 with respect to a direction in which theflexible display 310 is unwound.

The guide member 800 guides the flexible display 310 at a side oppositeto the display guide 920 with respect to the flexible display 310interposed between the guide member 800 and the display guide 920. Theguide member 800 may, for example, guide the flexible display 310 toproceed in a horizontal direction after passing through the opening 400.

Inclination of the guide member 800 may be designed in consideration ofa curvature by which the flexible display 310 is bendable. That is, theinclination of the guide member 800 may be designed to have a curvaturegreater than the maximum curvature of the flexible display 310. As such,even when the flexible display 310 bent by a certain curvature by theguide member 800 passes through the opening 400, fatigue due to thebending may not accumulated in the flexible display 310.

FIG. 9 is a side cross-sectional view of the electronic device 101according to an embodiment.

Referring to FIG. 9, a push member 900 is illustrated. The roll 300 ispositioned between the display guide 920 and the push member 900. Thepush member 900 pushes the roll 300 toward the display guide 920 in sucha manner that the flexible display 310 wound on the roll 300 contactsthe supporting surface 921.

In FIG. 9, the push member 900 pushes the flexible display 310 wound onthe roll 300. The push member 900 may contact the flexible display 310or the side protector 320. The push member 900 may be provided in theform of a roller that rotates as the roll 300 rotates, to reducefrictional contact with the flexible display 310 or the side protector320 (see FIG. 3).

The push member 900 may push the roll 300 toward the display guide 920due to a self weight thereof. As illustrated in FIG. 9, an elasticmember 910 for applying elastic force to the push member 900 in adirection capable of pushing the roll 300 toward the display guide 920may be further provided.

The display guide 920 supports the flexible display 310 wound on theroll 300, and guides the flexible display 310 unwound from the roll 300,toward the opening 400.

The flexible display 310 may be pushed by the push member 900 andsupported by the display guide 920 and thus may be stably held in awound state on the roll 300. In addition, even when the flexible display310 is wound on or unwound from the roll 300, the push member 900 aidsstable extension and retraction of the flexible display 310 by reducingmovement of the roll 300 in directions other than a direction in whichthe roll 300 is rolled or unrolled.

A structure in which the roll 300 is pushed toward the display guide 920by using the push member 900 and the elastic member 910 may be appliedto the embodiment of FIG. 8 such that the flexible display 310 wound onthe roll 300 may be pushed toward the supporting surface 922 of thedisplay guide 920.

FIGS. 10 and 11 are side cross-sectional views of the electronic device101 according to an embodiment. The electronic device 101 of the currentembodiment may include a winding member for providing elastic force tothe roll 300 in such a manner that the roll 300 rotates in a directioncapable of winding the flexible display 310 thereon. Referring to FIGS.10 and 11, the winding member may be implemented by, for example, aspiral spring 1000.

An end of the spiral spring 1000 may be connected to the roll 300, andthe other end thereof may be connected to the housing 200.Alternatively, the end of the spiral spring 1000 may be connected to theroll 300 and the other end thereof may be connected to the central shaft330. In this case, the roll 300 has a structure rotatable with respectto the central shaft 330, and the central shaft 330 does not rotate withrespect to the housing 200 but is merely supported by the housing 200 tomove along the roll guide 340. In the current embodiment, the other endof the spiral spring 1000 is connected to the central shaft 330.

Referring to FIG. 11, when the flexible display 310 starts to extend outof the housing 200, the roll 300 rotates in a counterclockwisedirection. The spiral spring 1000 accumulates elastic force as the roll300 rotates. The elastic force accumulated by the spiral spring 1000 isused to retract the flexible display 310 extended out of the housing200, into the housing 200 to wind the flexible display 310 on the roll300.

The electronic device 101, which retracts the flexible display 310 intothe housing 200 by using the spiral spring 1000, may include a lockingunit capable of holding the flexible display 310 in an extended state.FIG. 12 is a structural view of a locking unit according to anembodiment.

Referring to FIG. 12, the locking unit may be implemented by a stopperprojection 1200 and a stopper lever 1210. The stopper projection 1200 isprovided on the roll 300. The stopper projection 1200 may be provided ata side or two sides of the roll 300. As necessary, a plurality ofstopper projections 1200 may be provided in a rotation direction of theroll 300. The number of stopper projections 1200 may be determined inconsideration of a diameter of the roll 300 or a length of the flexibledisplay 310. For example, when the plurality of stopper projections 1200are provided, a length of the flexible display 310 extending out of thehousing 200 may be adjusted in multiple stages.

The stopper lever 1210 may be provided on the housing 200.Alternatively, in a structure in which the central shaft 330 issupported by the housing 200 and the roll 300 rotates with respect tothe central shaft 330, the stopper lever 1210 may be provided on thecentral shaft 330. In the current embodiment, the stopper lever 1210 isprovided on the central shaft 330.

An end of the stopper lever 1210 is rotatably supported by the centralshaft 330. The stopper lever 1210 may rotate to a contact location(indicated by a solid line in FIG. 12) at which the other end of thestopper lever 1210 contacts the stopper projection 1200, and a releaselocation (indicated by a two-dot chain line in FIG. 12) at which theother end of the stopper lever 1210 is released from the stopperprojection 1200. The spring 1220 provides elastic force to the stopperlever 1210 in a direction capable of holding the stopper lever 1210 atthe contact location.

Referring to FIG. 12, when the roll 300 rotates in a counterclockwisedirection to extend the flexible display 310 out of the housing 200, thestopper projection 1200 contacts the stopper lever 1210 mounted on thecentral shaft 330. In this state, when the roll 300 further rotates inthe counterclockwise direction, the stopper lever 1210 is pushed by thestopper projection 1200 and rotates in a direction opposite to adirection of the elastic force of the spring 1220.

As the stopper lever 1210 is pushed by the stopper projection 1200 androtates, a length of a superposed part between the stopper lever 1210and the stopper projection 1200 is gradually reduced. When the roll 300further rotates in the counterclockwise direction, the stopper lever1210 is positioned at the release location, the stopper projection 1200is released from the stopper lever 1210, and the roll 300 maycontinuously rotate in the counterclockwise direction. The stopper lever1210 returns to the contact location due to the elastic force of thespring 1220.

When the roll 300 stops rotating in the counterclockwise direction, theroll 300 rotates in a clockwise direction due to the elastic force ofthe spiral spring 1000. As the roll 300 rotates in the clockwisedirection, the stopper projection 1200 contacts the stopper lever 1210.The stopper lever 1210 may rotate from the contact location to therelease location, but is restricted so as not to rotate beyond thecontact location. A restriction member for the restriction may beimplemented by, for example, a restriction slot 1230 provided in thecentral shaft 330, and a restriction protrusion 1240 provided on thestopper lever 1210 and inserted into the restriction slot 1230.Accordingly, when the stopper projection 1200 rotates in the clockwisedirection and contacts the stopper lever 1210 positioned at the contactlocation, the roll 300 may no more rotate in the clockwise direction andthe display 310 is held in an extended state.

The electronic device 101 needs to release a locked state of the stopperlever 1210 and the stopper projection 1200 to retract the held display310 into the housing 200. For example, the electronic device 101 mayrotate the stopper lever 1210 to the release location. To this end,although not shown in FIG. 12, to allow a user to manually manipulateand rotate the stopper lever 1210 to the release location, a part of thestopper lever 1210 may be exposed outside the housing 200. In addition,although not shown in FIG. 12, a release lever for manually manipulatingand rotating the stopper lever 1210 exposed outside the housing 200, tothe release location may be further provided.

FIGS. 13 and 14 are side cross-sectional views of the electronic device101 according to an embodiment.

Referring to FIGS. 13 and 14, the push member 900 may be implemented bya roll spring 1300. The roll spring 1300 is supported by the roll guide340 and pushes the roll 300 toward the display guide 920. The rollspring 1300 pushes the central shaft 330.

The flexible display 310 wound on the roll 300 is held in contact withthe display guide 920, by the roll spring 1300. Therefore, the flexibledisplay 310 may be held in a wound state on the roll 300. In addition,as the flexible display 310 is unwound from the roll 300, the roll 300may more easily move downward and the flexible display 310 may be heldin contact with the display guide 920.

The push member 900 and the elastic member 910 of FIG. 9 may be appliedto the electronic device 101 illustrated in FIGS. 13 and 14. As such,the flexible display 310 may be more stably held in a wound state on theroll 300.

The electronic device 101 illustrated in FIGS. 13 and 14 may include aspiral spring (not shown) between the roll 300 and the central shaft330. The spiral spring may be provided at the same location as and mayperform the same function as the spiral spring 1000 described above inrelation to FIGS. 10 and 11.

The electronic device 101, which retracts the flexible display 310 intothe housing 200 by using the spiral spring 1000, may include a lockingunit capable of holding the flexible display 310 in an extended state.The locking unit may hold the extended flexible display 310. The lockingunit may be implemented by the stopper projection 1200 and the stopperlever 1210 described above in relation to FIG. 12.

When the flexible display 310 enters and exits the housing 200 throughthe opening 400, a certain relationship may be established betweenrotation of the roll 300 and movement of the roll 300 along the rollguide 340.

Referring to FIG. 15, a pinion gear 1500 is illustrated. The pinion gear1500 may be provided on, for example, the roll 300. In a structure inwhich the central shaft 330 rotates together with the roll 300, thepinion gear 1500 may be provided on the central shaft 330. In thecurrent embodiment, the pinion gear 1500 is provided on the centralshaft 330. The pinion gear 1500 engages with a rack gear 1510 extendingin a movement direction of the roll 300, i.e., an extension direction ofthe roll guide 340. The rack gear 1510 is positioned at a fixedlocation. For example, the rack gear 1510 may be provided on the housing200. As the flexible display 310 is wound on or unwound from the roll300, the pinion gear 1500 may move along the rack gear 1510 in anextension direction of the rack gear 1510.

The pinion gear 1500 may be designed to move along the rack gear 1510 bya variation in an outer diameter of the roll 300 including the flexibledisplay 310, when the flexible display 310 is wound on the roll 300 in amultilayer structure. That is, when the flexible display 310 wound onthe roll 300 is unwound or further wound by a layer, the roll 300 maymove along the roll guide 340 by a thickness of the flexible display 310such that a proceeding direction of the flexible display 310 withrespect to the opening 400 may be constantly maintained.

When a diameter of the pinion gear 1500 is Dp, the number of turns ofthe pinion gear 1500 is Np, and a movement distance of the pinion gear1500 along the rack gear 1510 is L,L=Dp*π*Np  Equation (1)

is satisfied.

Referring to FIG. 16, the pinion gear 1500 moves along the rack gear1510 and is positioned at a location under the location of FIG. 15, andthe flexible display 310 is in an extended state. As described above,the pinion gear 1500 may move by an increase or a reduction in thethickness of the flexible display 310 wound on or unwound from the roll300. Therefore, while the roll 300 is moving together with the piniongear 1500, a proceeding direction of the flexible display 310 toward theopening 400 may be constantly maintained.

The electronic device 101 according to the current embodiment mayinclude a display guide (not shown), a push member (not shown), and anelastic member (not shown) for appropriate extension and retraction ofthe flexible display 310. The display guide, the push member, and theelastic member of the current embodiment may be provided at the samelocations as and may perform the same functions as the display guide920, the push member 900, and the elastic member 910 described above inrelation to FIG. 9.

The electronic device 101 according to the current embodiment mayinclude a spiral spring (not shown) for interconnecting the roll 300 andthe central shaft 330. The spiral spring of the current embodiment maybe provided at the same location as and may perform the same function asthe spiral spring 1000 described above in relation to FIGS. 10 and 11.

The electronic device 101, which retracts the flexible display 310 intothe housing 200 by using the spiral spring 1000, may include a lockingunit capable of holding the flexible display 310 in an extended state.The locking unit may hold the extended flexible display 310. The lockingunit may employ a structure of the stopper projection 1200 and thestopper lever 1210 described above in relation to FIG. 12.

In a structure including only the rack gear 1510 and the pinion gear1500, the diameter of the pinion gear 1500 is reduced in proportion tothe thickness of the flexible display 310. Therefore, in considerationof production errors and durability of the pinion gear 1500, a gearreduction structure may be interposed between the rack gear 1510 and thepinion gear 1500.

FIG. 17 is a structural view of a reduction structure according to anembodiment.

Referring to FIG. 17, a reduction gear 1720 is interposed between thepinion gear 1500 and the roll 300.

The reduction gear 1720 is a double gear including a first gear part1721 engaging with the pinion gear 1500, and a second gear part 1722engaging with the rack gear 1510. A diameter of the first gear part 1721is greater than a diameter of the second gear part 1722. Although notshown in FIG. 17, the reduction gear 1720 may be provided on a bracket(not shown) for rotatably supporting the roll 300. The bracket issupported by the housing 200 to move together with the roll 300.

When the diameter of the first gear part 1721 is D1 and the diameter ofthe second gear part 1722 is D2, the pinion gear 1500 is connected tothe rack gear 1510 at a reduction gear ratio of D2/D1. Therefore, when adiameter of the pinion gear 1500 is Dp1, a movement distance of the roll300 is L1, and the number of turns of the pinion gear 1500 is Np,L1=Dp1*(D2/D1)*Np*π  Equation (2)

is satisfied.

Herein, if L of Equation (1) equals L1 of Equation (2), the diameter Dp1of the pinion gear 1500 satisfies

Dp1=(D1/D2)*Dp. Since D1>D2, Dp1>Dp is satisfied. Therefore, since thediameter of the pinion gear 1500 may be increased by (D1/D2) times, thepinion gear 1500 having a size appropriate for production may beemployed by appropriately selecting the diameters of the first andsecond gear parts 1721 and 1722, and durability of the pinion gear 1500may be increased.

As necessary, two or more reduction gears may be employed. FIG. 18 is astructural view of a reduction structure according to an embodiment.Referring to FIG. 18, first and second reduction gears 1820 and 1830 areinterposed between the pinion gear 1500 and the rack gear 1510.

The first reduction gear 1820 is a double gear including first andsecond gear parts 1821 and 1822. The second reduction gear 1830 is adouble gear including third and fourth gear parts 1831 and 1832. Thefirst gear part 1821 engages with the pinion gear 1500. The second gearpart 1822 engages with the third gear part 1831. The fourth gear part1832 engages with the rack gear 1510.

A diameter of the first gear part 1821 is greater than a diameter of thesecond gear part 1822. A diameter of the third gear part 1831 is greaterthan a diameter of the fourth gear part 1832. Although not shown in FIG.18, the first and second reduction gears 1820 and 1830 may be providedon a bracket (not shown) for rotatably supporting the roll 300. Thebracket is supported by the housing 200 to move together with the roll300.

When the diameters of the first, second, third, and fourth gear parts1821, 1822, 1831, and 1832 are D1, D2, D3, and D4, respectively, thepinion gear 1500 is connected to the rack gear 1510 at a reduction gearratio of (D2/D1)*(D4/D3). Therefore, when a diameter of the pinion gear1500 is Dp2, a movement distance of the roll 300 is L2, and the numberof turns of the pinion gear 1500 is Np,L2=Dp2*(D2/D1)*(D4/D3)*Np*π  Equation (3)

is satisfied.

Herein, if L of Equation (1) equals L2 of Equation (3), the diameter Dp1of the pinion gear 1500 satisfies Dp2=(D1/D2)*(D3/D4)*Dp. Since D1>D2and D3>D4, Dp2>Dp is satisfied. Therefore, since the diameter of thepinion gear 1500 may be increased by (D1/D2)*(D3/D4) times, the piniongear 1500 having a size appropriate for production may be employed byappropriately selecting the diameters of the first to fourth gear parts1821, 1822, 1831, and 1832, and durability of the pinion gear 1500 maybe increased. In addition, since gear reduction occurs twice, when Dp1equals Dp2, the first and second reduction gears 1820 and 1830 may havesizes less than a size of the reduction gear 1720 and thus a compactgear reduction structure applicable to a small space may be implemented.

FIG. 19 includes perspective views showing usage of the electronicdevice 101 using the afore-described structures. Herein, the electronicdevice 101 may be, for example, a rollable TV or screen.

Referring to FIG. 19(a), the electronic device 101 may be fixed to awall in such a manner that the opening 400 faces downward. The flexibledisplay 310 is completely wound on the roll 300 and accommodated in thehousing 200. The roll 300 is positioned, for example, at a rear end ofthe roll guide 340. A user may extend the flexible display 310 out ofthe housing 200 by holding and pulling downward the handle 210positioned at a front end of the flexible display 310.

FIG. 19(b) shows that the flexible display 310 partially extendsdownward through the opening 400 of the housing 200. FIG. 19(c) showsthat the flexible display 310 mostly extends downward through theopening 400 of the housing 200. As illustrated in FIGS. 19(b) and 19(c),the roll 300 moves forward along the roll guide 340 as the flexibledisplay 310 is unwound from the roll 300 and extends through the opening400, and reaches a front end of the roll guide 340 when the flexibledisplay 310 completely extends. When the flexible display 310 is woundon the roll 300, a wound length of the flexible display 310 on the roll300 is increased and the roll 300 moves backward along the roll guide340. Therefore, even when the wound length of the flexible display 310on the roll 300 varies, a proceeding direction of the flexible display310 with respect to the opening 400 in the housing 200 may be constantlymaintained.

FIG. 20 includes perspective views of the electronic device 101according to an embodiment. Referring to FIG. 20, the electronic device101 includes a pair of housings 200 and 200′, and rolls 300 and 300′ areprovided in the housings 200 and 200′, respectively. An end of theflexible display 310 is fixed to the roll 300 and the other end thereofis fixed to the roll 300′. The flexible display 310 is wound on therolls 300 and 300′ and accommodated in the housings 200 and 200′.Openings 400 and 400′ through which the flexible display 310 enters andexits are provided in the housings 200 and 200′, respectively. Thehousings 200 and 200′ are positioned in such a manner that the openings400 and 400′ face each other. Roll guides 340 and 340′ for guiding therolls 300 and 300′ are provided in the housings 200 and 200′,respectively. Due to the above-described configuration, the flexibledisplay 310 may extend out of/retract into the housings 200 and 200′ bypulling/pushing the housings 200 and 200′ away from/toward each other.

FIG. 20(a) shows that the flexible display 310 is accommodated in thehousings 200 and 200′. The housings 200 and 200′ closely contact eachother. In this state, when the housings 200 and 200′ are pulled awayfrom each other, as illustrated in FIG. 20(b), the flexible display 310is unwound from the rolls 300 and 300′, extends through the openings 400and 400′, and is spread between the housings 200 and 200′. When thehousings 200 and 200′ are pulled away from each other by the maximumdistance, as illustrated in FIG. 20(c), the flexible display 310 iscompletely unwound from the rolls 300 and 300′ and spread between thehousings 200 and 200′, thereby ensuring the widest image display area.

The roll guides 340 and 340′ extend in a vertical direction. The rolls300 and 300′ move downward along the roll guides 340 and 340′ as theflexible display 310 is unwound from the rolls 300 and 300′, and arepositioned at lower ends of the roll guides 340 and 340′ when theflexible display 310 is completely spread. When the housings 200 and200′ are pushed toward each other, the rolls 300 and 300′ rotate indirections for winding the flexible display 310 thereon due to, forexample, elastic force of the spiral spring 1000. When a wound length ofthe flexible display 310 on the rolls 300 and 300′ is increased, therolls 300 and 300′ move upward along the roll guides 340 and 340′.Therefore, even when the wound length of the flexible display 310 on therolls 300 and 300′ varies, proceeding directions of the flexible display310 with respect to the openings 400 and 400′ in the housings 200 and200′ may be constantly maintained.

Each of the above-described elements of the electronic device accordingto various embodiments may include one or more components, and the namesof the elements may vary depending on the type of the electronic device.The electronic device according to various embodiments may include atleast one of the above-described elements and may not include someelements or may further include additional elements. Furthermore, someof the elements of the electronic device according to variousembodiments may be combined to configure a single entity, and the singleentity may equally perform functions of the combined elements.

The invention claimed is:
 1. An electronic device comprising: a housinghaving an opening; a roll mounted in the housing; a flexible displaywound on the roll and being extendable and retractable through theopening based on a rotation direction of the roll; and a roll guideconfigured to guide the roll to align a proceeding direction of theflexible display with the opening in the housing, based on a variationin a diameter of wound flexible display on the roll.
 2. The electronicdevice of claim 1, further comprising a central shaft configured as anaxis of rotation of the roll, wherein the roll guide guides the centralshaft.
 3. The electronic device of claim 1, further comprising a windingmember configured to provide elastic force upon the roll in a directioncapable of winding the flexible display on the roll.
 4. The electronicdevice of claim 3, further comprising a locking unit configured to lockthe roll so as to prevent rotation of the roll in a direction of theelastic force of the winding member.
 5. The electronic device of claim4, wherein the locking unit comprises: a stopper projection provided onthe roll; and a stopper lever comprising: a release location whereinterference with the stopper projection is released, and a contactlocation where the stopper lever is obstructed by the stopper projectionto stop rotation of the roll.
 6. The electronic device of claim 1,wherein the roll guide is configured to guide the roll in a directionperpendicular to the proceeding direction of the flexible display towardthe opening in the housing.
 7. The electronic device of claim 1, whereinthe roll guide is configured to guide the roll diagonally to a directionperpendicular to the proceeding direction of the flexible display towardthe opening in the housing.
 8. The electronic device of claim 1, furthercomprising a display guide comprising a supporting surface configuredto: support the flexible display, and guide the flexible display unwoundfrom the roll, toward the opening in the housing.
 9. The electronicdevice of claim 8, further comprising a guide member configured to guidethe flexible display at a side opposite to the display guide withrespect to the flexible display interposed between the guide member andthe display guide.
 10. The electronic device of claim 9, wherein theguide member is configured to guide the flexible display in a horizontaldirection after passing through the opening in the housing.
 11. Theelectronic device of claim 8, further comprising a push memberconfigured to push the roll toward the display guide such that theflexible display wound on the roll contacts the supporting surface. 12.The electronic device of claim 11, further comprising an elastic memberconfigured to provide elastic force upon the push member to push thepush member toward the display guide.
 13. The electronic device of claim11, wherein the push member comprises a roller rotating in contact withthe flexible display.
 14. The electronic device of claim 8, wherein thepush member comprises a roll spring supported by the roll guide andconfigured to push the roll toward the display guide.
 15. The electronicdevice of claim 1, further comprising: a pinion gear rotating togetherwith the roll; and a rack gear connected to the pinion gear andextending in an extension direction of the roll guide.